The sprout inhibitor 1,4-dimethylnaphthalene induces the expression of the cell cycle inhibitors KRP1 and KRP2 in potatoes.

The suppression of sprout growth is critical for the long-term storage of potato tubers. 1,4-Dimethylenapthlene (DMN) is a new class of sprout control agent but the metabolic mode of action for this compound has yet to be elucidated. Changes in transcriptional profiles of meristems isolated from potato tubers treated with the DMN were investigated using an Agilent 44 K 60-mer-oligo microarray. RNA was isolated from nondormant Russet Burbank meristems isolated from tubers treated with DMN for 3 days or activated charcoal as a control. RNA was used to develop probes that were hybridized against a microarray developed by the Potato Oligo Chip Initiative. Analysis of the array data was conducted in two stages: total array data was examined using a linear model and the software Limma and pathway analysis was conducted by linking the potato sequences to the Arabidopsis thaliana. DMN elicited a change in a number of transcripts associated with cold responses, water regulation, salt stress, and osmotic adjustment. DMN also resulted in a repression of cyclin or cyclin-like transcripts. DMN also resulted in a 50% decrease in thymidine incorporation suggesting a repression of the S phase of the cell cycle. Quantitative real-time polymerase chain reaction analysis demonstrated that DMN increased transcripts for the cell cycle inhibitors KRP1 and KRP2. We conclude the DMN results in alteration of genes associated with the maintenance of a G1/S phase block possibly through the induction of the cell cycle inhibitors KRP1 and KRP2.

Prehistoric mitochondrial DNA of domesticate animals supports a 13th century exodus from the northern US southwest.

The 13th century Puebloan depopulation of the Four Corners region of the US Southwest is an iconic episode in world prehistory. Studies of its causes, as well as its consequences, have a bearing not only on archaeological method and theory, but also social responses to climate change, the sociology of social movements, and contemporary patterns of cultural diversity. Previous research has debated the demographic scale, destinations, and impacts of Four Corners migrants. Much of this uncertainty stems from the substantial differences in material culture between the Four Corners vs. hypothesized destination areas. Comparable biological evidence has been difficult to obtain due to the complete departure of farmers from the Four Corners in the 13th century CE and restrictions on sampling human remains. As an alternative, patterns of genetic variation among domesticated species were used to address the role of migration in this collapse. We collected mitochondrial haplotypic data from dog (Canis lupus familiaris) and turkey (Meleagris gallopavo) remains from archaeological sites in the most densely-populated portion of the Four Corners region, and the most commonly proposed destination area for that population under migration scenarios. Results are consistent with a large-scale migration of humans, accompanied by their domestic turkeys, during the 13th century CE. These results support scenarios that suggest contemporary Pueblo peoples of the Northern Rio Grande are biological and cultural descendants of Four Corners populations.